Purpose: The objective of this study is to evaluate capillary blood flow of the juxtapapillary retina and neuroretinal rim area in primary open angle glaucoma (POAG) by a new noninvasive method performing a high-definition topography of perfused vessels of the retina and the optic nerve head with simultaneous evaluation of blood flow.
Methods: Juxtapapillary retinal and neuroretinal rim area blood flow were measured by scanning laser Doppler flowmetry (SLDF). This new technique is a combination of a laser Doppler flowmeter with a scanning laser system by which the retinal perfusion is simultaneously quantified in 16,000 sites of a retinal area of 2.7 x 0.7 mm. In study I, retinal and optic nerve head blood flow were evaluated by SLDF in 43 patients with POAG and 43 healthy individuals. The mean age of the POAG group was 56 +/- 12 years and of the control group 42 +/- 15 years. In study II, age-matched normals (n = 21) were compared with glaucoma eyes with topical therapy (n = 30) and with glaucoma eyes without topical therapy (n = 16).
Results: In study I, the eyes with POAG had an average cup/disc ratio (C/D) of 0.75 +/- 0.20, with an average mean defect of the visual field of 5.3 +/- 5.4 dB. The actual intraocular pressure was 17.8 +/- 4.18 mm Hg in the POAG group and 15.45 +/- 1.82 mm Hg in the control group. For statistical analysis, two age-matched groups of 28 normal eyes of 28 persons with 27 glaucomatous eyes of 27 patients were compared. In normals the blood flow of the neuroretinal rim area was significantly higher than that of the juxtapapillary retinal area (+7.73%, p < 0.01). In POAG both juxtapapillary retinal blood flow and neuroretinal rim area blood flow were significantly decreased compared to an age-matched control group: neuroretinal rim area flow -71% and juxtapapillary retina flow -49%. The decrease of neuroretinal rim area blood flow did significantly correlate with C/D. We found no correlation between reduction of juxtapapillary retinal blood flow and C/D or mean defect. Both glaucoma eyes with and glaucoma eyes without topical therapy showed significant decreased juxtapapillary blood flow compared to normals. We found no significant difference in the juxtapapillary blood flow between glaucoma eyes with and without topical therapy.
Conclusions: In POAG, optic nerve head blood flow and juxtapapillary blood flow were significantly decreased.